pair<int, int> p[4];
        for(int i = 0; i < 4; i++) {
            p[i] = make_pair(si, sj);
        }
        int di[] = {-1, 0, 1, 0};
        int dj[] = {0, -1, 0, 1};
        int ret = 0;
        for(int i = 0; i < 4; i++) {
            if(p[i].first + di[i] >= 0 and p[i].first + di[i] < n and p[i].second + dj[i] >= 0 and p[i].second + dj[i] < m) {
                p[i].first += di[i];
                p[i].second += dj[i];
                ret += mat[p[i].first][p[i].second];
            }

        }
        int S = ret;
        for(int G = 0; G < 60; G++) {
            int tmp = S;
            for(int i = 0; i < 4; i++) {
                if(p[i].first + di[i] >= 0 and p[i].first + di[i] < n and p[i].second + dj[i] >= 0 and p[i].second + dj[i] < m) {
                    p[i].first += di[i];
                    p[i].second += dj[i];

                }
            }
        }